1. Field of the Invention
The preset invention relates to a process application robot system having a function for managing a process condition.
2. Description of the Related Art
In a processing-use robot system (or a process application robot system) of the prior art, a plurality of operation modes may be managed, wherein the modes are switched by means of a switch, etc., provided to a process controller or a robot controller, or the modes are switched by an operator using a password login function of software of the controller. For example, in a lower level operation mode or under predetermined conditions, a change in important settings having an affect on welding quality may be limited, whereby a trouble, such as an incorrect setting or a change in setting unrecognized or unintended by a user in an upper level or a system manager, can be prevented. Therefore, the system can be safely managed and operated.
As relevant prior art documents, JP 2007-210007 A discloses a technique in which an operation regarding a welding power source is limited, corresponding to respective lock modes selected by a key switch of the welding power source.
Further, WO 2012/157157 A1 discloses a technique in which whether or not welding conditions can be changed is determined, depending on a connection stated between a welding condition setter and a welding power source, and on contents of a change-permission setting of the welding power source.
In a conventional process application robot system, first, in an upper level operation mode in which there is no (or few) operation limitation, a process program is generated or taught, and a process condition is set. Then, after the robot system is started up and brought to a production stage, the robot system is operated in a lower level operation mode in which minimal operations, such as starting and stopping the process program, etc., can be carried out. By virtue of this, the process application system at the production stage can be protected from incorrect setting or a change in setting unrecognized or unintended by a system manager, by which processing quality may be affected.
In fact, the position and orientation in teaching and the process condition are often to be fine-tuned after the production stage. The reason thereof varies depending on the application such as arc welding or spot welding. For example, in the arc welding, a target position may be varied due to a placement error or a dimension error or an object to be welded, and an amount of heat input of the object or a jig may be varied due to continuous welding during the production stage. Therefore, it is desired that stable process conditions be constituted while taking into consideration various external factors after the production stage.
On the other hand, even when the present process conditions do not include any problem, there may be a situation where the process state should be checked when a command current is slightly increased or decreased. When such a situation occurs, the operator must switch the operation mode to the upper level, whereby the operability is lowered. In particular, when the robot controller and the process controller are located away from a production site by a considerable distance, it is cumbersome for the operator to move from the production site to the controller in order to switch the operation mode.